150 Experiments to determine 



of fired gunpowder computed by the above rule would 

 be much too small. 



In the experiment No. 84, when the charge consisted 

 of 1 8 grains of powder, and the density, or value of x 

 was 702, a weight equal to the pressure of 10,977 at- 

 mospheres was raised. Here the value of y (= x *+-*-*^ 

 is found to be (7O2 1 - 2808 ), = 4421.7; and to express this 

 value of y in atmospheres, and at the same time to 

 accommodate it to the actual result of the experiment, 

 it must be multiplied by 2.4826; for it is 4421.7 (the 

 value of y expressed in equal parts) to 10,977 (its value 

 in atmospheres, as shewn by the experiment), as i to 

 2.4826, and consequently 4421.7 X 2.4826= 10,977. 



If now the value of y be computed on the same 

 principles, when x is put = 1000, it will turn out to be 

 y = iooo I + 4 = 15,849; and this number expressed 

 in atmospheres, by multiplying it by 2.4826, gives the 

 value of ^ = 39, 346 atmospheres. 



This, however, falls still far short of 54,752 atmos- 

 pheres, the force the powder was actually found to exert 

 when the charge filled the space in which it was confined. 

 But in the 84th experiment, when 18 grains of powder 

 were used, as the weight (8081 Ibs. avoirdupois) was 

 raised with a very loud report^ it is more than probable 

 that the force of the generated elastic fluid was in fact 

 considerably greater than that at which it was estimated, 

 namely, greater than the pressure of 10,977 atmospheres. 



But, without wasting time in fruitless endeavours to 

 reconcile anomalous experiments, which, probably, never 

 can be made to agree, I shall hasten to give an account 

 of another set of experiments ; the results of which, it 

 must be confessed, were still more various, extraordinary, 

 and inexplicable. 



